CIRCADIAN RHYTHM IN THE PRODUCTION AND RELEASE OF MICROCYSTINS, EXPRESSION OF mcyE GENE AND PHYSIOLOGICAL STRESS IN CYANOBACTERIA: IMPLICATIONS OF GLOBAL CLIMATE CHANGES

• Grant number: 15/17397-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: March 01, 2016
• End date: August 31, 2019
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: Maria Do Carmo Bittencourt de Oliveira
• Grantee: Micheline Kézia Cordeiro de Araújo
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated scholarship(s): 17/15769-9 - The influence of UV radiation and high temperature on the carbon dioxide sequestration and microcystins production by Microcystis strains, BE.EP.PD

Abstract

Because of recurring events associated with global climate changes, several combined factors have been favored formation of toxic cyanobacteria blooms and increase of cyanotoxins production. Microcystins (MC) are cyanotoxins widely distributed in drinking water sources all over the world, with a story of several human intoxication cases and deaths. In this regard, it is endowed with great scientific interest the investigation of processes driven by circadian rhythms (endogenous processes) and ecophysiological processes, both involved in microcystins production and release. In this sense, the results could be used to establish mitigating measures for aquatic ecosystems, as well as help in formulating management and accident prevention strategies. The goal of this study is the evaluation of combined effects related to light intensity, temperature and exposure to ultraviolet radiation (UV-B), all of them driven by climate change conditions, on circadian rhythms of microcystin production and release. Additionally, expression of mcyE gene, oxidative stress and growth of Microcystis aeruginosa (BCCUSP232) and Sphaerospermopsis aphanizomenoides (BCCUSP55) will be examined. Experiments will be performed under controlled conditions, simulating several climate change scenarios at 24h cycles (light:dark, 12:12h) along the exponential growth phase of cyanobacteria. Samples will be collected at 4 h intervals during the cycles. Data will be analyzed by taking into account combined effects associated with circadian rhythms in MC production and release per cell-quota, mcyE gene expression, oxidative stress (oxygen reactive species production, catalase, superoxide dismutase and peroxidase activities) and cyanobacteria growth. Statistical tests will be employed according with data normality and homogeneity.

Scientific publications

(5)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CORDEIRO-ARAUJO, MICHELINE KEZIA; CHIA, MATHIAS AHII; DE TOLEDO ARRUDA-NETO, JOAO DIAS; TORNISIELO, VALDEMAR LUIZ; VILCA, FRANZ ZIRENA; BITTENCOURT-OLIVEIRA, MARIA DO CARMO. Microcystin-LR bioaccumulation and depuration kinetics in lettuce and arugula: Human health risk assessment. Science of The Total Environment, v. 566, p. 1379-1386, OCT 1 2016. (13/11306-3, 14/01934-0, 15/17397-6)

CORDEIRO-ARAUJO, MICHELINE KEZIA; CHIA, MATHIAS AHII; BITTENCOURT-OLIVEIRA, MARIA DO CARMO. Potential human health risk assessment of cylindrospermopsin accumulation and depuration in lettuce and arugula. HARMFUL ALGAE, v. 68, p. 217-223, SEP 2017. (13/11306-3, 14/01934-0, 15/17397-6)

CORDEIRO-ARAUJO, MICHELINE KEZIA; LORENZI, ADRIANA STURION; CHIA, MATHIAS AHII; MOTA, ELIANE CHRISTINA; BITTENCOURT-OLIVEIRA, MARIA DO CARMO. nsights into the impact of increasing temperature, light intensity, and UV-B exposure on the circadian rhythm of microcystin production and release, and the expression of mcy genes in the cyanobacterium Microcystis aeruginos. JOURNAL OF APPLIED PHYCOLOGY, v. 34, n. 1, NOV 2021. (13/15296-2, 17/15769-9, 15/17397-6, 14/01913-2)

LORENZI, ADRIANA STURION; CORDEIRO-ARAUJO, MICHELINE KEZIA; CHIA, MATHIAS AHII; BITTENCOURT-OLIVEIRA, MARIA DO CARMO. Cyanotoxin contamination of semiarid drinking water supply reservoirs. ENVIRONMENTAL EARTH SCIENCES, v. 77, n. 16, AUG 2018. (13/11306-3, 14/01913-2, 15/17397-6)

CHIA, MATHIAS AHII; CORDEIRO-ARAUJO, MICHELINE KEZIA; LORENZI, ADRIANA STURION; BITTENCOURT-OLIVEIRA, MARIA DO CARMO. Cylindrospermopsin induced changes in growth, toxin production and antioxidant response of Acutodesmus acuminatus and Microcystis aeruginosa under differing light and nitrogen conditions. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY, v. 142, p. 189-199, AUG 2017. (13/11306-3, 13/15296-2, 15/17397-6, 14/26898-6, 14/01934-0)